JP6385680B2 - Light emitting element - Google Patents

Description

  Embodiments relate to a light emitting device.

  An LED (Light Emitting Diode), which is a typical example of a light emitting element, is an element that converts an electrical signal into a form of infrared, visible light, or light using the characteristics of a compound semiconductor. It is used for display devices, various automation devices, etc., and its usage area is gradually expanding.

  In general, a miniaturized LED is manufactured in a surface mount device type so as to be directly mounted on a PCB (Printed Circuit Board) board. Therefore, an LED lamp used as a display element is also a surface. It has been developed as a mounting element type. Such a surface-mount element can replace an existing simple lighting lamp, which is used for a lighting display, a character display, a video display, and the like that emit various colors.

  As described above, as the use area of the LED becomes wider, the luminance required for electric lamps used in daily life, rescue signal lamps, and the like increases. Therefore, it is important to increase the emission luminance of the LEDs.

  In addition, the electrode of the light emitting element must have excellent adhesion and electrical characteristics.

  In addition, research for increasing the luminance of the light emitting element and reducing the operating voltage is ongoing.

  Embodiments provide a light emitting device that reduces the VF of the light emitting device and improves the light emission efficiency.

  The light emitting device according to the embodiment includes: a conductive substrate; a first electrode layer disposed on the conductive substrate; a first semiconductor layer disposed on the first electrode layer; a second semiconductor layer; A light emitting structure comprising an active layer positioned between the first semiconductor layer and the second semiconductor layer; a second electrode layer electrically connected to the second semiconductor layer; and the first electrode The layer includes an ohmic layer comprising: a transparent electrode layer disposed between the conductive substrate and the first semiconductor layer; and a plurality of metal contact portions that vertically penetrate the transparent electrode layer, The metal contact portion includes AuBe.

  The window layer further includes a window layer between the first electrode layer and the light emitting structure, and the window layer is a dopant having the same polarity as the polarity of the first semiconductor layer in a region where the metal contact portion is in contact. A doping region doped with

  And the area on the plane of the said transparent electrode layer can be made larger than the area on the plane of the said metal contact part.

  Meanwhile, the doping region may protrude from the surface of the window layer.

  The light emitting device according to the embodiment has an advantage that ohmic contact with the light emitting structure can be easily made by arranging the metal contact portion so as to penetrate the transparent electrode layer.

  Further, since the metal contact portion penetrates the transparent electrode layer, there is an advantage that heat generated in the light emitting structure is easily discharged to the conductive substrate.

  Further, since the metal contact portion is in direct contact with the light emitting structure, there is an advantage that VF (Voltage Forward) is lowered.

  Since the area of the metal contact portion is smaller than the area of the transparent electrode layer, there is an advantage that the probability of hindering the progress of light reflected by the metal reflection layer is reduced and the light emission efficiency is improved.

  In addition, since the embodiment is doped with impurities only in the region where the metal contact portion contacts, there is an advantage that an ohmic contact is formed without greatly reducing the light efficiency.

It is sectional drawing which shows the light emitting element which concerns on one Embodiment of this invention. FIG. 2 is a cross-sectional plan view with respect to the ohmic layer cut along the line AA in FIG. 1. It is sectional drawing which shows the light emitting element which concerns on other one Embodiment of this invention. It is sectional drawing which shows the light emitting element which concerns on another one Embodiment of this invention. It is sectional drawing which shows the light emitting element which concerns on another one Embodiment of this invention. 1 is a perspective view of a light emitting device package including a light emitting device according to an embodiment. It is sectional drawing of the light emitting element package containing the light emitting element which concerns on embodiment. It is a perspective view which shows the illumination system containing the light emitting element which concerns on embodiment. It is the C-C 'sectional view taken on the line of the illumination system of FIG. It is a disassembled perspective view of the liquid crystal display device containing the light emitting element which concerns on embodiment. It is a disassembled perspective view of the liquid crystal display device containing the light emitting element which concerns on embodiment.

  Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described in detail below in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and can be embodied in various different forms. However, this embodiment is provided in order to complete the disclosure of the present invention and to fully inform those who have ordinary knowledge in the technical field to which the present invention pertains the scope of the invention. It is only defined by the category of the term. Like reference numerals refer to like elements throughout the specification.

  Spatial relative terms “below”, “beeneath”, “lower”, “above”, “upper” etc. are shown in the drawing As such, it can be used to easily describe the correlation between one element or component and another element or component. Spatial relative terms should be understood as terms that include different directions of the element in use or operation in addition to the directions shown in the drawings. For example, if the element shown in the drawing is flipped over, the element described as “below” or “beneath” of the other element is placed “above” the other element. Can do. Thus, the exemplary term “bottom” can include both the bottom and top directions. The elements can also be oriented in other directions so that spatially relative terms can be interpreted by orientation.

  The terminology used herein is for the purpose of describing embodiments and is not intended to limit the invention. In this specification, the singular includes the plural unless specifically stated otherwise. As used herein, “comprises” and / or “comprising” refers to a component, stage, operation and / or element referred to is one or more other components, stages, operations And / or does not exclude the presence or addition of elements.

  Unless otherwise defined, all terms used herein (including technical and scientific terms) can be commonly understood by those having ordinary skill in the art to which this invention belongs. Can be used as meaning. Also, terms defined in commonly used dictionaries are not ideally or excessively interpreted unless specifically defined otherwise.

  In the drawings, the thickness and size of each layer are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Moreover, the size and area of each component do not completely reflect the actual size or area.

  In the embodiments, the angles and directions referred to in the process of describing the structure of the light-emitting element are based on those described in the drawings. In the specification, in the description of the structure forming the light emitting element, when the reference point and the positional relationship with respect to the angle are not explicitly mentioned, the related drawings are referred to.

  FIG. 1 is a cross-sectional view illustrating a light emitting device according to an embodiment, and FIG. 2 is a plan cross-sectional view with respect to an ohmic layer taken along the line AA in FIG.

  Referring to FIG. 1, the light emitting device 100 according to the embodiment includes a conductive substrate 110, a first electrode layer 120 disposed on the conductive substrate 110, and a first electrode disposed on the first electrode layer 120. The light emitting structure 140 including the semiconductor layer 141, the second semiconductor layer 145, and the active layer 143 positioned between the first semiconductor layer 141 and the second semiconductor layer 145 is electrically connected to the second semiconductor layer 145. And the second electrode layer 150.

The conductive substrate 110 may support the light emitting structure 140 and provide power to the light emitting structure 140 together with the second electrode layer 150. The conductive substrate 110 can be formed of a material having excellent thermal conductivity or a conductive material. For example, gold (Au), nickel (Ni), tungsten (W), molybdenum (Mo), copper (Cu). , Aluminum (Al), tantalum (Ta), silver (Ag), platinum (Pt), chromium (Cr), Si, Ge, GaAs, ZnO, GaN, Ga ₂ O ₃ or SiC, SiGe, CuW It can be formed of any one of them, or can be formed of two or more alloys, and can be formed by stacking two or more different materials. That is, the conductive substrate 110 may be embodied as a carrier wafer.

  Such a conductive substrate 110 can easily release heat generated from the light emitting device 100 and improve the thermal stability of the light emitting device 100.

  In the embodiment, the conductive substrate 110 is described as having conductivity. However, the conductive substrate 110 may not have conductivity and is not limited thereto.

  A first electrode layer 120 that supplies power to the light emitting structure 140 is included on the conductive substrate 110. A detailed description of the first electrode layer 120 will be described later.

  A window layer 130 may be further disposed on the first electrode layer 120 to reduce a difference in reflectance between the first electrode layer 120 and the light emitting structure 140.

  The window layer 130 increases light extraction efficiency by reducing a difference in reflectance between the light emitting structure 140 and the first electrode layer 120.

  Specifically, the window layer 130 is located between the first semiconductor layer 141 and the first electrode layer 120.

  The window layer 130 may include any one of GaP, GaAsP, and AlGaAs.

  The light emitting structure 140 includes a first semiconductor layer 141, a second semiconductor layer 145, and an active layer 143 between the first semiconductor layer 141 and the second semiconductor layer 145.

The second semiconductor layer 145 may be implemented by an n-type semiconductor layer, and the n-type semiconductor layer may be, for example, In _x Al _y Ga _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, A semiconductor material having a composition formula of 0 ≦ x + y ≦ 1), for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, etc., can be selected, for example, Si, Ge, Sn, Se, Te N-type dopants may be doped. The second semiconductor layer 145 may be selected from a semiconductor material having a composition formula of (Al _X Ga _1-X ) _0.5 In _0.5 P.

  Meanwhile, a second electrode layer 150 electrically connected to the second semiconductor layer 145 may be disposed on the second semiconductor layer 145, and the second electrode layer 150 may include at least one pad or / and a predetermined number. An electrode having a pattern can be included. The second electrode layer 150 may be disposed in the center region, the outer region, or the corner region of the upper surface of the second semiconductor layer 145, but is not limited thereto. The second electrode layer 150 can be disposed not in the second semiconductor layer 145 but in another region, and is not limited thereto.

  The second electrode layer 150 is made of a conductive material such as In, Co, Si, Ge, Au, Pd, Pt, Ru, Re, Mg, Zn, Hf, Ta, Rh, Ir, W, Ti, Ag, Cr. , Mo, Nb, Al, Ni, Cu, and WTi can be used to form a single layer or multiple layers.

  A concavo-convex pattern 160 for improving light extraction efficiency may be formed by a predetermined etching method on a partial region or the entire region of the surface of the second semiconductor layer 145 where the second electrode layer 150 is not formed. it can.

  Here, the second electrode layer 150 is described as being formed on a flat surface on which the concave / convex pattern 160 is not formed. However, the second electrode layer 150 may be formed on an upper surface on which the concave / convex pattern 160 is formed, and is not limited thereto. Not.

  The uneven pattern 160 can be formed by performing etching on at least one region of the upper surface of the second semiconductor layer 145, but is not limited thereto. The etching process includes a wet or / and dry etching process, and the upper surface of the second semiconductor layer 145 may include the uneven pattern 160 through the etching process. The uneven pattern 160 may be irregularly formed in a random size, but is not limited thereto. The concavo-convex pattern 160 may be at least one of a texture pattern, a concavo-convex pattern, and a non-planar pattern.

  The concavo-convex pattern 160 can be formed so that the side section has various shapes such as a cylinder, a polygonal column, a cone, a polygonal pyramid, a truncated cone, and a polygonal truncated cone, and includes a cone shape.

  On the other hand, the uneven pattern 160 can be formed by a method such as PEC (photoelectrochemical), but is not limited thereto. The uneven pattern 160 is formed on the upper surface of the second semiconductor layer 145, so that the light generated from the active layer 143 is totally reflected from the upper surface of the second semiconductor layer 145 and reabsorbed or scattered. Since this can be prevented, the light extraction efficiency of the light emitting element 100 can be improved.

  An active layer 143 can be formed under the second semiconductor layer 145. The active layer 143 is a region where electrons and holes are recombined, and transitions to a low energy level by recombination of electrons and holes, and can generate light having a wavelength corresponding thereto. .

The active layer 143 includes, for example, a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). It can be formed with a single quantum well structure or a multiple quantum well (MQW) structure. The active layer 143 may be selected from a semiconductor material having a composition formula of (Al _X Ga _1-X ) _0.5 In _0.5 P.

  Therefore, more electrons gather at the low energy level of the quantum well layer, and as a result, the recombination probability between electrons and holes increases, and the light emitting effect can be improved. Further, a quantum wire (Quantum wire) structure or a quantum dot (Quantum dot) structure may be included.

A first semiconductor layer 141 can be formed under the active layer 143. The first semiconductor layer 141 may be implemented with a p-type semiconductor layer and inject holes into the active layer 143. For example, the p-type semiconductor layer is a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), for example, GaN, It can be selected from AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, etc., and may be doped with a p-type dopant such as Mg, Zn, Ca, Sr, Ba. In addition, the first semiconductor layer 141 may be selected from semiconductor materials having a composition formula of (Al _X Ga _1-X ) _0.5 In _0.5 P.

  A third semiconductor layer (not shown) may be formed under the first semiconductor layer 141. Here, the third semiconductor layer may be realized by a semiconductor layer having a polarity opposite to that of the second semiconductor layer.

  On the other hand, the second semiconductor layer 145, the active layer 143, and the first semiconductor layer 141 described above are formed by metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), or plasma chemical vapor deposition. Using PECVD (Plasma-Enhanced Chemical Vapor Deposition), Molecular Beam Growth (MBE), Molecular Beam Epitaxy (hydride vapor phase epitaxy), HVPE (hydride vapor phase epitaxy), etc. However, the present invention is not limited to this.

  In addition, unlike the above, in the embodiment, the second semiconductor layer 145 may be implemented with a p-type semiconductor layer and the first semiconductor layer 141 may be implemented with an n-type semiconductor layer, but is not limited thereto. Accordingly, the light emitting structure 140 may include at least one of an NP junction, a PN junction, an NPN junction, and a PNP junction structure.

  In addition, a passivation 170 may be formed so that a partial region or an entire region of the outer peripheral surface of the light emitting structure 140 is protected from an external impact or the like and an electrical short circuit can be prevented.

Referring to FIGS. 1 and 2, the first electrode layer 120 may selectively use a metal and a light-transmitting conductive layer, and provide a power source for the light emitting structure 140. The first electrode layer 120 can be formed including a conductive material. For example, nickel (Ni), platinum (Pt), ruthenium (Ru), iridium (Ir), rhodium (Rh), tantalum (Ta), molybdenum (Mo), titanium (Ti), silver (Ag), tungsten (W ), Copper (Cu), chromium (Cr), palladium (Pd), vanadium (V), cobalt (Co), niobium (Nb), zirconium (Zr), indium tin oxide (ITO, indium tin oxide), aluminum zinc Oxides (AZO, aluminum zinc oxide), Indium zinc oxide (IZO), IZTO (indium zinc zinc oxide), IAZO (indium aluminum zinc oxide), IGZO (indium zinc oxide) ide), IGTO (indium gallium tin oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IrO x, RuO x, RuO x / ITO, Ni / IrO x / Au or Ni / _IrO x / Au, / It can be formed of at least one of ITO. However, it is not limited to this.

  The first electrode layer 120 may include at least one of an ohmic layer 123 (ohmic layer) and a metal reflective layer 125 (reflective layer). In addition, the first electrode layer 120 may include at least one of an ohmic layer 123 (ohmic layer), a metal reflective layer 125 (reflective layer), and a metal adhesion layer 121.

  For example, the first electrode layer 120 may have a configuration in which a metal reflective layer 125 and an ohmic layer 123 are sequentially stacked on the metal adhesive layer 121. FIG. 1 shows a form in which an ohmic layer 123 is laminated on the metal adhesive layer 121.

  The ohmic layer 123 may include a transparent electrode layer 123A disposed between the conductive substrate 110 and the light emitting structure 140, and a plurality of metal contact portions 123B penetrating the transparent electrode layer 123A vertically.

The transparent electrode layer 123A may be made of a material that transmits light reflected by the conductive substrate 110 or the metal reflective layer 125 and has conductivity. For example, the transparent electrode layer 123A may include at least one of In ₂ O ₃ , SnO ₂ , ZnO, ITO, CTO, CuAlO ₂ , CuGaO _2, and SrCu ₂ O ₂ .

  A large number of metal contact portions 123B are arranged through the transparent electrode layer 123A in the vertical direction. The multiple metal contact parts 123B are regularly spaced apart from each other. The metal contact portion 123B is in ohmic contact with the light emitting structure 140.

  In addition, at least one surface of the metal contact portion 123B may be in contact with the first semiconductor layer 141 of the light emitting structure 140, and the other surface may be in contact with the conductive substrate 110.

  The metal contact portion 123B includes AuBe. Of course, the metal contact portion 123B may include Au or an Au alloy.

  When the metal contact portion 123B is disposed through the transparent electrode layer 123A, there is an advantage that ohmic contact with the light emitting structure 140 is easily performed. Further, since the metal contact portion 123B penetrates the transparent electrode layer 123A, there is an advantage that heat generated in the light emitting structure 140 is easily discharged to the conductive substrate 110.

  Further, since the metal contact portion 123B is in direct contact with the light emitting structure 140, there is an advantage that VF (Voltage Forward) is lowered. In particular, compared with a case where the metal contact portion 123B does not penetrate the transparent electrode layer 123A, there is an effect that the operating voltage is reduced by about 10%. This is because the transparent electrode layer 123A has lower conductivity than the metal contact portion 123B.

  In particular, referring to FIG. 2, the area of the transparent electrode layer 123A on the plane is preferably larger than the area of the metal contact portion 123B on the plane. More preferably, the area of the metal contact portion 123B on the plane may be 10% to 25% relative to the area of the transparent electrode layer 123A on the plane. When the area on the plane of the metal contact portion 123B is smaller than 10% of the area on the plane of the transparent electrode layer 123A, ohmic contact between the light emitting structure 140 and the first electrode layer 120 is difficult, and the metal contact portion 123B When the area on the plane is larger than 25% of the area on the plane of the transparent electrode layer 123A, there is a problem in that the light efficiency of the light emitting device 100 is lowered due to the metal contact portion 123B having a low light transmittance.

  In order for the area on the plane of the metal contact portion 123B to be 10% to 25% relative to the area on the plane of the transparent electrode layer 123A, for example, the separation distance between the adjacent metal contact portions 123B is 35 μm to 50 μm. The width of the metal contact portion 123B is preferably 10 μm to 20 μm.

  The shape of the metal contact portion 123B is not particularly limited, but may have a rod shape. Preferably, it has a cylindrical or polygonal column shape.

  The first electrode layer 120 may be flat as shown in FIG. 1, but is not limited thereto, and may have a step.

  The first electrode layer 120 may further include a metal adhesion layer 121.

  The metal adhesive layer 121 can be formed under the ohmic layer 123 to enhance the adhesive force between the layers. The metal adhesion layer 121 can be formed using a material having excellent adhesion with the lower material. For example, any one of PbSn alloy, AuGe alloy, AuBe alloy, AuSn alloy, Sn, In, SnIn alloy and PdIn alloy can be included.

  In addition, a diffusion preventing film (not shown) can be further formed on the metal adhesive layer 121. The diffusion prevention film can prevent the material forming the conductive substrate 110 and the metal adhesion layer 121 from diffusing into the light emitting structure 140. The diffusion prevention film can be formed of a material that prevents metal diffusion, for example, platinum (Pt), palladium (Pd), tungsten (W), nickel (Ni), ruthenium (Ru), molybdenum (Mo). , Iridium (Ir), rhodium (Rh), tantalum (Ta), hafnium (Hf), zirconium (Zr), niobium (Nb), vanadium (V), or at least one alloy may be used. it can. However, it is not limited to this. The metal adhesive layer 121 may have a single layer or a multilayer structure.

  FIG. 3 is a cross-sectional view showing a light emitting device according to another embodiment of the present invention.

  Referring to FIG. 3, the light emitting device 100 </ b> A according to the embodiment further includes a metal reflection layer 125 and a current blocking layer 180 as compared with the embodiment of FIG. 1.

  The first electrode layer 120 further includes a metal reflection layer 125. The metal reflection layer 125 is formed under the ohmic layer 123 and reflects light toward the conductive substrate 110 out of light reflected by the active layer 143 to the upper portion of the light emitting structure 140.

  The metal reflection layer 125 is made of a material having excellent reflection characteristics, for example, Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, or Hf, or a selective combination thereof. It can be formed of a material, or can be formed in multiple layers using a metal material and a light-transmitting conductive material such as IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO. The reflective layer (not shown) can be laminated with IZO / Ni, AZO / Ag, IZO / Ag / Ni, AZO / Ag / Ni, or the like.

The current blocking layer 180 is disposed under the light emitting structure 140 so that at least one region overlaps the second electrode layer 150 in the vertical direction, and has a lower electrical conductivity than the ohmic layer 123 and the metal reflective layer 125. it can. The current blocking layer 180 is made of, for example, aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), titanium oxide (TiO _x ), indium tin oxide (ITO, indium tin oxide). In addition, at least one of aluminum zinc oxide (AZO) and indium zinc oxide (IZO) may be included. However, it is not limited to this.

  The current blocking layer 180 is an electron blocking layer that prevents a phenomenon in which electrons injected from the second semiconductor layer 145 into the active layer 143 are not recombined in the active layer 143 and flow into the first electrode layer 120 when a high current is applied. Electron blocking layer). Since the current blocking layer 180 has a relatively larger band gap than the active layer 143, electrons injected from the second semiconductor layer 145 are injected into the first semiconductor layer 141 without being recombined in the active layer 143. The phenomenon can be prevented. Accordingly, the recombination probability between electrons and holes can be increased in the active layer 143, and leakage current can be prevented.

  FIG. 4 is a cross-sectional view showing a light emitting device according to another embodiment of the present invention.

  Referring to FIG. 4, the light emitting device 100 </ b> B according to the embodiment is different from the embodiment of FIG. 1 in that a doping region 133 is further formed in the window layer 130.

  At this time, in the window layer 130, a doping region 133 doped with impurities may be formed in a region where the metal contact portion 123B is in contact.

  The doping region 133 is formed in a region where the metal contact portion 123B is in contact with the window layer 130, and is preferably doped with a dopant having the same polarity as that of the first semiconductor layer 141. Here, since it is assumed that the first semiconductor layer 141 is doped with a p-type dopant, the description will be made on the basis that the doping region 133 is doped with a p-type dopant.

  When the window layer 130 is doped, the light transmittance decreases, but the ability to make ohmic contact with the metal contact portion 123B increases. Therefore, since the doping region 133 is formed only in the region in contact with the metal contact portion 123B in the window layer 130, the window layer 130 and the metal contact portion 123B come into ohmic contact.

  Further, since the doping region 133 is reduced in the window layer 130, the light transmittance is not greatly reduced. As a result, the formation of the doping region 133 in the window layer 130 does not significantly reduce the light transmittance of the window layer 130 and enables ohmic contact between the window layer 130 and the metal contact portion 123B.

  In addition, since the window layer 130 and the metal contact portion 123B are in ohmic contact with each other, the operating voltage of the light emitting device 100 is lowered, and the light transmittance of the window layer 130 is not significantly reduced. is there.

  The p-type dopant doped in the doping region 133 of the window layer 130 may include any one of Mg, Zn, Ca, Sr, Ba, and C.

When the doping region 133 is doped at an excessively high concentration, the light transmittance is significantly reduced. When the doping region 133 is doped at an excessively low concentration, ohmic contact between the window layer 130 and the metal contact portion 123B may be difficult. Therefore, when the doping region 133 is doped with Mg, the doping concentration is 5 × 10 ¹⁸ / cm ³ to 1 × 10 ¹⁸ / cm ³ , and when doped with C, the doping concentration is 5 × 10 ¹⁹ / cm 3. It is preferably ³ to 1 × 10 ¹⁹ / cm ³ .

  The doping regions 133 are spaced apart from each other in the form of dots or islands in the window layer 130. Since the arrangement of the doping region 133 corresponds to the arrangement of the metal contact portion 123B, only the metal contact portion 123B will be described below.

  The doping region 133 may be formed at a certain depth on the surface of the window layer 130. Further, the doping region 133 may protrude from the surface of the window layer 130. That is, the surface of the window layer 130 is etched in the process of doping the entire surface of the window layer 130 and etching the region excluding the doping region 133, and the doping region 133 can protrude from the surface of the window layer 130. However, it is not limited to this.

  The area on the plane of the doping region 133 is formed to be the same as the area on the plane of the metal contact portion 123B described above. If the area on the plane of the doping region 133 is too small, it is difficult for the window layer 130 and the metal contact portion 123B to make ohmic contact, and if it is too wide, the light efficiency of the light emitting device is greatly reduced.

  Of course, the separation distance between the adjacent doping regions 133 can be the same as the separation distance between the metal contact portions 123B.

  FIG. 5 is a cross-sectional view showing a light emitting device according to another embodiment of the present invention.

  Referring to FIG. 5, the light emitting device 100 </ b> C of the embodiment is different from the embodiment of FIG. 3 in that a doping region 133 is further formed in the window layer 130.

  The description of the doping region 133 is as described above.

  FIG. 6 is a perspective view illustrating a light emitting device package including the light emitting device according to the embodiment, and FIG. 7 is a cross-sectional view illustrating the light emitting device package including the light emitting device according to the embodiment.

  Referring to FIGS. 6 and 7, the light emitting device package 500 includes a body 510 having a cavity 520, first and second lead frames 540 and 550 mounted on the body 510, and first and second leads. A light emitting element 530 electrically connected to the frames 540 and 550 and a sealing material (not shown) filled in the cavity 520 so as to cover the light emitting element 530 may be included.

The body 510 is made of a resin material such as polyphthalamide (PPA), silicon (Si), aluminum (Al), aluminum nitride (AlN), a liquid crystal polymer (PSG), polyamide 9T (PA9T), Shinji. It can be formed of at least one of tactic polystyrene (SPS), a metal material, sapphire (Al ₂ O ₃ ), beryllium oxide (BeO), and a printed circuit board (PCB). The body 510 can be formed by injection molding, an etching process, or the like, but is not limited thereto.

  The inner surface of the body 510 can be an inclined surface. The angle of reflection of light emitted from the light emitting element 530 varies depending on the angle of the inclined surface, and thus the directivity angle of light emitted to the outside can be adjusted.

  As the light directivity angle decreases, the concentration of light emitted from the light emitting element 530 to the outside increases. Conversely, as the light directivity angle increases, the concentration of light emitted from the light emitting element 530 to the outside increases. Decrease.

  On the other hand, the shape of the cavity 520 formed in the body 510 viewed from above may be a circular shape, a quadrangular shape, a polygonal shape, an elliptical shape or the like, or a shape with curved corners. It is not limited to this.

  The light emitting device 530 is mounted on the first lead frame 540 and may be, for example, a light emitting device that emits light such as red, green, blue, or white, or a UV (Ultra Violet) light emitting device that emits ultraviolet light. However, it is not limited to this. One or more light emitting elements 530 can be mounted.

  In addition, the light emitting device 530 is either a horizontal type in which all the electrical terminals are formed on the upper surface (Horizontal type), a vertical type (Vertical type) formed on the upper or lower surface, or a flip chip. It may be.

  A sealing material (not shown) can fill the cavity 520 so as to cover the light emitting element 530.

  The sealing material (not shown) can be formed of silicon, epoxy, or other resin material, and can be formed by filling the cavity 520 with ultraviolet or heat curing.

  Further, the sealing material (not shown) can include a phosphor, and the type of the phosphor is selected according to the wavelength of light emitted from the light emitting element 530, and the light emitting element package 500 is white light. Can be realized.

  Such phosphors are blue light-emitting phosphors, blue-green light-emitting phosphors, green light-emitting phosphors, yellow-green light-emitting phosphors, yellow light-emitting phosphors, yellow-red phosphors according to the wavelength of light emitted from the light-emitting element 530. Any one of a light emitting phosphor, an orange light emitting phosphor, and a red light emitting phosphor can be applied.

  That is, the phosphor can be excited by light having the first light emitted from the light emitting element 530 to generate the second light. For example, when the light emitting element 530 is a blue light emitting diode and the phosphor is a yellow phosphor, the yellow phosphor can be excited by blue light to emit yellow light, The light emitting device package 500 can provide white light by being mixed with yellow light generated by excitation with the blue light.

  Similarly, in the case where the light emitting element 530 is a green light emitting diode, a case where a magenta phosphor or a blue and red phosphor is mixed can be cited as an example, and the light emitting element 530 is a red light emitting diode. In some cases, a cyan phosphor or a mixture of blue and green phosphors may be used as an example.

  Such phosphors include YAG, TAG, sulfide, silicate, aluminate, nitride, carbide, nitride silicate, borate, fluoride, phosphate, etc. The known phosphor may be used.

  The first and second lead frames 540 and 550 are made of a metal material such as titanium (Ti), copper (Cu), nickel (Ni), gold (Au), chromium (Cr), tantalum (Ta), platinum (Pt ), Tin (Sn), silver (Ag), phosphorus (P), aluminum (Al), indium (In), palladium (Pd), cobalt (Co), silicon (Si), germanium (Ge), hafnium (Hf) ), Ruthenium (Ru), iron (Fe), or an alloy thereof. In addition, the first and second lead frames 540 and 550 can be formed to have a single layer structure or a multilayer structure, but are not limited thereto.

  The first and second lead frames 540 and 550 are electrically separated from each other. The light emitting device 530 is mounted on the first and second lead frames 540 and 550, and the first and second lead frames 540 and 550 are in direct contact with the light emitting device 530 or a soldering member (not shown). May be electrically connected through a conductive material such as The light emitting device 530 may be electrically connected to the first and second lead frames 540 and 550 by wire bonding, but is not limited thereto. Accordingly, when a power source is connected to the first and second lead frames 540 and 550, the power source can be applied to the light emitting device 530. Meanwhile, a plurality of lead frames (not shown) may be mounted in the body 510, and each lead frame (not shown) may be electrically connected to the light emitting device 530, but is not limited thereto.

  FIG. 8 is a perspective view illustrating a lighting device including the light emitting element according to the embodiment, and FIG. 9 is a cross-sectional view taken along the line CC ′ of the lighting device of FIG.

  Referring to FIGS. 8 and 9, the lighting device 600 may include a body 610, a cover 630 fastened to the body 610, and end caps 650 positioned at both ends of the body 610.

  The light emitting device module 640 is fastened to the lower surface of the body 610, and the body 610 has excellent conductivity and heat dissipation so that heat generated from the light emitting device package 644 is released to the outside through the upper surface of the body 610. It can be made of a metallic material.

  The light emitting device package 644 can be mounted on the PCB 642 in multiple colors and multiple rows to form an array, and can be mounted at the same interval or with various separation distances as required. , Brightness etc. can be adjusted. As such a PCB 642, MPPCB (Metal Core PCB) or PCB made of FR4 material can be used.

  Since the light emitting device package 644 includes an extended lead frame (not shown), the light emitting device package 644 can have an improved heat dissipation function. Therefore, reliability and efficiency of the light emitting device package 644 can be improved, and light emission can be achieved. The service life of the lighting device 600 including the element package 644 and the light emitting element package 644 can be extended.

  The cover 630 may be formed in a circular shape so as to surround the lower surface of the body 610, but is not limited thereto.

  The cover 630 protects the internal light emitting element module 640 from external foreign matter and the like. In addition, the cover 630 may include diffusing particles so as to prevent glare of light generated from the light emitting device package 644 and to uniformly emit light to the outside, and at least of the inner surface and the outer surface of the cover 630. A prism pattern or the like can be formed on any one surface. In addition, a phosphor may be applied to at least one of the inner surface and the outer surface of the cover 630.

  On the other hand, since light generated from the light emitting device package 644 is emitted to the outside through the cover 630, the cover 630 must have excellent light transmittance and can withstand heat generated from the light emitting device package 644. Must have sufficient heat resistance. Therefore, the cover 630 is preferably formed of a material including polyethylene terephthalate (PET), polycarbonate (Polycarbonate; PC), or polymethyl methacrylate (PMMA).

  The end caps 650 are positioned at both ends of the body 610 and can be used for sealing a power supply device (not shown). Further, since the power pin 652 is formed on the end cap 650, the lighting device 600 according to the embodiment can be used immediately without a separate device at the terminal from which the existing fluorescent lamp is removed.

  FIG. 10 is an exploded perspective view of a liquid crystal display device including the light emitting element according to the embodiment.

  FIG. 10 illustrates an edge-light method, and the liquid crystal display device 700 may include a liquid crystal display panel 710 and a backlight unit 770 for providing light to the liquid crystal display panel 710.

  The liquid crystal display panel 710 can display an image using light provided from the backlight unit 770. The liquid crystal display panel 710 may include a color filter substrate 712 and a thin film transistor substrate 714 that face each other with the liquid crystal interposed therebetween.

  The color filter substrate 712 may embody the color of an image displayed through the liquid crystal display panel 710.

  The thin film transistor substrate 714 is electrically connected via a driving film 717 to a printed circuit board 718 on which a large number of circuit components are mounted. The thin film transistor substrate 714 can apply a driving voltage provided from the printed circuit board 718 to the liquid crystal in response to a driving signal provided from the printed circuit board 718.

  The thin film transistor substrate 714 may include a thin film transistor and a pixel electrode formed as a thin film on another substrate made of a transparent material such as glass or plastic.

  The backlight unit 770 includes a light emitting element module 720 that outputs light, a light guide plate 730 that changes the light provided from the light emitting element module 720 into a surface light source and provides the light to the liquid crystal display panel 710, and the light guide plate 730. A number of films 752, 766, 764 that make the luminance distribution of the provided light uniform and improve vertical incidence, and a reflection sheet 747 that reflects light emitted behind the light guide plate 730 to the light guide plate 730. Composed.

  The light emitting device module 720 may include a plurality of light emitting device packages 724 and a PCB substrate 722 on which the plurality of light emitting device packages 724 are mounted to form an array. In this case, the mounting reliability of the bent light emitting element package 724 can be improved.

  Meanwhile, the backlight unit 770 includes a diffusion film 766 that diffuses light incident from the light guide plate 730 in the direction of the liquid crystal display panel 710, and a prism film 752 that condenses the diffused light and improves vertical incidence. A protective film 764 for protecting the prism film 752 can be included.

  FIG. 11 is an exploded perspective view of a liquid crystal display device including the light emitting element according to the embodiment. However, the parts illustrated and described in FIG. 10 will not be described in detail repeatedly.

  FIG. 11 illustrates a direct method, and the liquid crystal display device 800 may include a liquid crystal display panel 810 and a backlight unit 870 for providing light to the liquid crystal display panel 810.

  The liquid crystal display panel 810 is the same as that described with reference to FIG.

  The backlight unit 870 includes a plurality of light emitting element modules 823, a reflective sheet 824, a lower chassis 830 in which the light emitting element modules 823 and the reflective sheet 824 are accommodated, and a diffusion plate 840 disposed on the light emitting element module 823. A plurality of optical films 860.

  The light emitting device module 823 may include a plurality of light emitting device packages 822 and a PCB substrate 821 on which the plurality of light emitting device packages 822 are mounted to form an array.

  The reflection sheet 824 reflects light generated from the light emitting element package 822 in a direction in which the liquid crystal display panel 810 is located, thereby improving light use efficiency.

  Meanwhile, light generated from the light emitting element module 823 is incident on the diffusion plate 840, and an optical film 860 is disposed on the diffusion plate 840. The optical film 860 may include a diffusion film 866, a prism film 850, and a protective film 864.

  Although the embodiment has been mainly described above, this is merely an example and is not intended to limit the present invention. Any person having ordinary knowledge in the field to which the present invention belongs can be used. It will be understood that various modifications and applications not exemplified above are possible without departing from the characteristics. For example, each component specifically shown in the embodiment can be modified. Such differences in modification and application should be construed as being included in the scope of the present invention as defined in the appended claims.

Claims (7)

A conductive substrate;
A first electrode layer disposed on the conductive substrate;
A light emitting structure comprising: a first semiconductor layer disposed on the first electrode layer; a second semiconductor layer; and an active layer positioned between the first semiconductor layer and the second semiconductor layer;
A window layer disposed between the first electrode layer and the first semiconductor layer to reduce a difference in reflection index between the first electrode layer and the first semiconductor layer;
A second electrode layer electrically connected to the second semiconductor layer,
The first electrode layer includes
A transparent electrode layer disposed between the conductive substrate and the first semiconductor layer;
Including an ohmic layer comprising a plurality of metal contact portions vertically penetrating the transparent electrode layer,
The metal contact portion includes AuBe,
The metal contact portion, at least one surface in contact with the window layer,
The window layer includes a doping region doped with a dopant having the same polarity as the polarity of the first semiconductor layer in a region where the metal contact portion is in contact,
The doping region is formed only in a region in contact with the metal contact in the window layer;
The light emitting device has a planar area of the doping region that is the same as a planar area of the metal contact portion .   The light emitting device according to claim 1, wherein the doping region protrudes from a surface of the window layer.   3. The light emitting device according to claim 1, wherein an area of the transparent electrode layer on a plane is larger than an area of the metal contact portion on a plane. The first electrode layer includes
A metal reflective layer and a metal adhesive layer disposed under the ohmic layer;
4. The light emitting device according to claim 1, wherein one surface of the metal adhesive layer is in contact with the conductive substrate.   The light emitting device according to claim 1, wherein the window layer includes one of GaP, GaAsP, and AlGaAs. The doped region is doped with a p-type dopant;
6. The light emitting device according to claim 1, wherein when the doping region is doped with Mg, a doping concentration is 5 × 10 ¹⁸ / cm ³ to 1 × 10 ¹⁸ / cm ³ . The doped region is doped with a p-type dopant;
6. The light emitting device according to claim 1, wherein when the doping region is doped with C, a doping concentration is 5 × 10 ¹⁹ / cm ³ to 1 × 10 ¹⁹ / cm ³ .

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